Heat exchanger

ABSTRACT

A heat exchanger comprising a feed water chamber and a steam chamber extending to a considerable extent into said water chamber in spaced relationship to the housing wall of said water chamber so that the latter has a bell-shaped contour with the skirt thereof placed in spaced relationship over a portion of the steam chamber, said water chamber being divided by a partition into two sections, one of which communicates with one end of a plurality of pipes in said steam chamber while the other water chamber section communicates with the other end of said pipes, feed water inlet and outlet means respectively communicating with said water chamber sections and being arranged in the skirt portion of said water chamber, and steam inlet and condensate outlet means being provided in said steam chamber.

United States Patent [191 Parussel 111] 3,814,178 1 1 June 4, 1974 1 HEAT EXCHANGER Horst Parussel, Ahrensburg, Germany [75] Inventor:

[73] Assignee: Cass International GmbH,

Hamburg, Germany [22] Filed: Nov. 1, 1971 [21] Appl. No.: 194,127

3,596.638 8/1971 Michelmlm FOREIGN PATENTS OR APPLICATIONS 1,153,780 9/1963 Germany 165/161 Primary Examiner-Charles J. Myhre Assistant Examiner-Theophil W. Streule, Jr. Attorney, Agent, or Firm-Walter Becker [5 7] ABSTRACT A heat exchanger comprising a feed water chamber and a steam chamber extending to a considerable extent into said water chamber in spaced relationship to the housing wall of said water chamber so that the latter has a bell-shaped contour with the skirt thereof placed in spaced relationship over a portion of the steam chamber, said water chamber being divided by a partition into two sections, one of which communicates with one end of a plurality of pipes in said steam chamber while the other water chamber section com:

municates with the other end of said pipes; feed water inlet and outlet means respectively communicating with said water chamber sections and being arranged in the skirt portion of said water chamber, and steam inlet and condensate outlet means being provided in said steam chamber.

2 Claims, 3 Drawing Figures 1 HEAT EXCHANGER The present invention relates to a heat exchanger for heating up liquids, especially water, with steam or hot gases. More specifically, the present invention concerns a heat exchanger of the just mentioned type which comprises a nest of tubes anchored in at least one tube plate and leading thereinto by means of a plurality of individual tubes. The heat exchanger furthermore comprises a longitudinally extending steam chamber mantle provided with steam inlet and outlet conduits which mantle is closed off at least on one side by a tube plate the tubes of which extend through the steam chamber confined by the steam mantle and communicate with a water chamber located on that side of the tube plate which faces away from the steam cham- Referring now to the drawings in detail, the heat exchangers comprise primarily a steam chamber 1 surrounded by a cylindrical mantle 2, and a water chamber 3 connected to the end of the steam chamber and confined by a mantle 4. Between the steam chamber 1 and the water chamber 3 there is provided a tube plate 5 in which the nest of tubes comprising many tubes or ber and provided with water inlet and outlet conduits I while being surrounded by a water chamber mantle.

in thermal power installations, especially in the nuclear reactor art, heat exchangers with ever increasing heat exchanging surfaces are required which have a considerable structural length. In order to keep the necessary space requirement to a minimum, there exists a considerable demand for heat exchangers which with a relatively short length have a large heat exchanging surface.

With heretofore customary heat exchangers equipped with nestsof tubes, considerable heat stresses occur in the tube plate which separates the primary part from the secondary part. These heat stressen are due to the fact that the marginal zones of the plate which are free from tubes or pipes adjust themselves to temperature variations of the medium flowing through i the pipes at a slower rate than do the central portions of the plate provided with pipes. These stresses which occur in particular on the surface of the tube plate have a disadvantageous effect upon the connection of the pipes with the plate and upon the connection of the plate with the housing surrounding same.

it is, therefore, an object of the present invention to provide a heat exchanger which in spite ofa large heat exchanging surface has a minimum length, and in which the heat stresses occuring in the pipe bottom are kept to a minimum.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a longitudinal section through one end of a heretofore customary heat exchanger.

FIG. 2 shows a longitudinal section through one end of a heat exchanger according to the invention.

FIG. 3 illustrates a modified type of welding connection in connection with a heat exchanger according to the invention.

The heat exchanger according to the present invention is characterized primarily in that the water chamber mantle in the manner of a bell having an edge or skirt portion and in spaced relationship to the end of the steam chamber mantle extends over the said end while the water supplying and withdrawing conduits are connected to that portion of the water chamber mantle which extends over the steam chamber mantle end.

According to a preferred embodiment of the invention, the steam chamber and water chamber have a substantially cylindrical cross section.

pipes 6 is so anchored that the tubes or pipes 6 lead into the water chamber 3. 97 consideration The central portion of the water chamber 3 is divided by a partition 9 into an inlet and an outlet part respectively communicating with a feed water inlet 7 and a feed water outlet 8.

The end face of the water chamber mantle 4 is formed by a bottom 10 which may be flat or arched and which has two inspection openings 11, 11' through which a portion of the water chamber 3 is accessible. The inspection or checking openings 11 are adapted to be closed by a cover.

The steam chamber mantle 2 is provided with a steam inlet opening 12 for feeding the hot steam into the steam chamber and is furthermore provided with an outlet opening 13 for the discharge of the condensate.

In the heretofore customary heat exchanger construction as shown in F IG. 1, the water chamber 3 has the same outer diameter as the steam chamber 1. The water chamber mantle 4 is welded to that side of the tube plate 5 which faces the water chamber mantle. lnasmuch as the feed water enters at 7 in radial direction and the feed water is discharged at 8 in radial direction, it is necessary to provide corresponding pipe connections between the plate 5 and the bottom 10. In this way the water chamber 3 will have a considerable extension in longitudinal direction as a result of which the heat exchanger has a great length. Moreover, the mutual zones of influence ofthe welding seams 13 have to be taken into consideration by increasing the structural length.

With the heat exchanger according to the invention and shown in FIG. 2, the water chamber mantle 4 has an edge or skirt portion which extends in a bell-shaped manner over that end of the steam chamber 1 which is provided with the tube plate 5 and does so in spaced relationship to said end. The tube plate 5 extends into the water chamber 3 to such an extent that the frictionless course of the water flow will not be disturbed by losses caused by a deviation of the flow. That portion of the water chamber mantle 4 which extends over the steam chamber mantle 2 is expediently of a cylindrical shape. lts length is selected so that the radially entering feed water and the radially leaving feed water will find suffcient space while taking into consideration the mutual zones of influence of the welding seams. it is by this cylindrical portion that the total length of the heat exchanger according to the present invention becomes shorter than the total length of the heat exchangers according to heretofore customary designs.

The feed water entering through the feed water inlet 7 flows along the outer surface of that end of the steam chamber mantle 2 which carries the tube plate 5 and enters the mouth of the pipes 6. While flowing through the nest of tubes, the feed water is heated up and in the upper portion of the water chamber 3 which is connected to the feed water outlet 8 is discharged again. Here the direction of flow is deviated in the direction toward the feed water outlet 8 so that the feed water flows in the region of the cylindrical portion of the water chamber mantle 4 around the end of the steam chamber mantle 2 and around the tube plate 5 These parts around which the feed water is flowing will eventually take on the temperature of the feed water so that no material temperature drops or temperature differences exist between the tube plate 5 and the adjacent portions of the steam chamber mantle 2. As a result thereof, the customary heat stresses which occur with heretofore known heat exchangers in the tube plate 5 and the inherent loosening of the pipe connections in pipe plate 5 will be avoided. I

In addition to the above, heat stresses in the steam chamber mantle 2 will be reduced due to the fact that that end of the steam chamber mantle 2 which is connected to the tube plate 5 will have free length of expansion. The firm clamping of this end in the water chamber mantle 4, as it is the case with heretofore known constructions of the type involved,.is eliminated according to the invention by the arrangement of the water chamber 3 in favor of a free displaceability.

The connection of the water chamber mantle 4 to the steam chamber mantle 2 is effected by a flange 14. This flange may be a prefabricated forging or rolling piece of such a shape that a cylindrical member adapted to be welded into the steam chamber mantle 2 has that surface thereof which faces the water chamber mantle 4 designed in .the form of an annular cup formed by an outwardly extending flange and a peripheral flange 14 parallel to the mantle. The free marginal area of the annular cup and the marginal area of the water chamber mantle 4 abut against each other and their edges are connected to each other by the welding seam 13.

The connecting flange 14 may be designed in conformity with FIG. 3 so as to form a ring. In this connection, the inner bore 15 of the ring is welded to the outer surface of the steam chamber mantle 2. The outer marginal area of the annular connecting flange 14 is cranked in the direction toward the water mantle chamber 4 and is connected thereto by means of the welding seam 13.

All heretofore known types of heat exchangers may be equipped with an arrangement of the water chamber 3 according to the present invention. Thus, for instance, all possible, especially square and rectangular cross sections are possible. Also with regard to the selection of the nest of tubes, all heretofore customary heat exchangers may be equipped with the arrangement of the water chamber 3 according to the invention. More specifically, this is possible with U-shaped tubular heat exchangers on one side only of the steam chamber 1, and with straight nests of tubes on both sides of the steam chamber 1. Also the way in which the steam passes through the nest of tubes will not affect the possibility to provide the arrangement of the water chamber 3 according to the invention at one or both ends of the steam chamber. Neither'the frequency of the deviation of the steam flow between steam inlet 12 and condensate outlet 13 nor the question whether the invention may also be used for the generation or the overheating of steam by means of a hot liquid passed through the nest of tubes. In particular in nuclear energy installations this type of heat exchanger is frequently employed.

It is, of course, to be understood that the present invention is, by no means, limited to the specific construction shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

l. A heat exchanger for heating liquids, especially water, by meansof hot media, particularly steam and hot gases, which includes in eom bination: a steam chamber comprising a first mantle forming a tubular confining wall for said steam chamber and also comprising plate means integral with one end of said mantle and closing said one end, a bell-shaped water mantle having a bottom and a skirt integral with said bottom and surrounding a portion of said first mantle in spaced relationship thereto, said bell-shaped water mantle forming a unitary part fastened exclusively at said skirt also having an annular housing section comprising an annular flange integral with and extending outwardly from said first mantle and a peripheral flange parallelto said first mantle extending toward said skirt with its end integrally connected to the free end of said skirt, partition means interposed between and connected to said plate means and said bottom of said bell-shaped water chamberand dividing the latter into two separate sections respectively provided with a feed water inlet and a feed water outlet provided in said skirt, said skirt projecting with a spacing in parallel wall relationship to the steam chamber mantle past the water inlet and water outlet, said inlet and outlet being integrally connected to said skirt between said annular flange and the bottom of said chamber and pipe means arranged in said steam chamber and having one end connected to and communicating through said plate means with one of said water chamber sections, the other end of said pipe means. being connected to and communicating through said plate means with the other section of said water chamber, said steam chamber being provided with steam inlet means and with condensate outlet means.

2. A heat exchanger in combination according to claim 1, in which each said steam first mantle and said water mantle'has a substantially cylindrical outer cont0ur. 

1. A heat exchanger for heating liquids, especially water, by means of hot media, pArticularly steam and hot gases, which includes in combination: a steam chamber comprising a first mantle forming a tubular confining wall for said steam chamber and also comprising plate means integral with one end of said mantle and closing said one end, a bell-shaped water mantle having a bottom and a skirt integral with said bottom and surrounding a portion of said first mantle in spaced relationship thereto, said bell-shaped water mantle forming a unitary part fastened exclusively at said skirt also having an annular housing section comprising an annular flange integral with and extending outwardly from said first mantle and a peripheral flange parallel to said first mantle extending toward said skirt with its end integrally connected to the free end of said skirt, partition means interposed between and connected to said plate means and said bottom of said bell-shaped water chamber and dividing the latter into two separate sections respectively provided with a feed water inlet and a feed water outlet provided in said skirt, said skirt projecting with a spacing in parallel wall relationship to the steam chamber mantle past the water inlet and water outlet, said inlet and outlet being integrally connected to said skirt between said annular flange and the bottom of said chamber and pipe means arranged in said steam chamber and having one end connected to and communicating through said plate means with one of said water chamber sections, the other end of said pipe means being connected to and communicating through said plate means with the other section of said water chamber, said steam chamber being provided with steam inlet means and with condensate outlet means.
 2. A heat exchanger in combination according to claim 1, in which each said steam first mantle and said water mantle has a substantially cylindrical outer contour. 